SERPINC1 and hereditary antithrombin deficiency: Moreover, the combined treatment of HepG2 cells with 1,25-dihydroxy-cholecalciferol [1,25-(OH)2VitD3] and all-trans retinoic acid (ATRA), stimulated the production of antithrombin [32].The identification in this study of three genetic modifications disturbing two different VDRE sequences in patients with moderate antithrombin deficiency supports a role for this regulatory pathway in the SERPINC1 transcriptional control.